I have TomTom Navigator 3 working off a HP Ipaq 2210 and the wired GPS receiver. Its mounted next to the front pillar of the car using the Car Kit I got aswell, (craddle with a suction pad for the window).
The wire for the GPS is hidden between the dash and the windscreen so no problems there. Only gripe I have is the power cord going to the Cig lighter, I have to stretch it over the top of the steering wheel.
As for the maps, the UK coverage is great, I've used it quite a few times for getting to places I've never been before and sometimes I use it for a bit of fun to see if it sends me the correct way when I know the route like the back of my hand.
I believe that TomTom do a European map package that you can buy, suppose if you wanted all of Europe you would need alot of memory to store the info, the full UK map takes up 101mb of my SD card.
If you want one I guess waiting for the Jan sales might be an option in case some places have them discounted. I picked my Ipaq, TomTom Software, Car Kit, GPS receiver and SD card up for ?299 from Dixons but that was when they had a special sale on over a bank holiday weekend.